This version provides many new features for troubleshooting and servicing the product, with a focus on the ability to automatically detect and recover from problems.
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Collecting Java dumps and core files using the administrative console
The Java virtual machine (JVM) is capable of producing Java dump and core files to aid
in troubleshooting. You can use heap dump and system dump files to
help you diagnose memory-related problems, such as memory leaks. You
can use Java core files to help
you diagnose problems where the CPU is persistently 100% busy, when
threads are hanging, or where threads are in a deadlock.
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Enabling request-level Reliability Availability and Serviceability (RAS) granularity
Reliability
Availability and Serviceability (RAS) granularity is the ability to
assign different RAS attribute values to different sets of requests
within the same application server. You can improve the reliability,
availability, and serviceability of the application server and the
requests it processes by using the request-level RAS granularity capabilities
introduced in Version 8.0 of
the product.
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High Performance Extensible Logging (HPEL)
- HPEL provides a convenient mechanism for storing
and accessing log, trace, System.err, and System.out information produced
by the application server or your applications. It is an alternative
to the basic log and trace facility, which provided the JVM logs,
diagnostic trace, and service log files commonly named SystemOut.log/SystemErr.log,
trace.log, and activity.log.
- HPEL provides a convenient mechanism
for storing and accessing log, trace, System.err, and System.out information
produced by the application server or your applications. It is an
alternative to the existing log and trace facilities offered on the
z/OS platform which exploit JES, LogStreams, Component Trace, Hierarchical
File System, or other facilities.
- HPEL has been designed and tested to significantly
outperform the existing basic log and trace facility. One result is
that the application server can run with trace enabled while causing
less impact to performance than tracing the same components using
basic logging. Another result is that applications that frequently
write to the logs might run faster with HPEL. A number of factors
contribute to the overall performance of HPEL logging and tracing.
- HPEL has
been designed to be easy to configure and understand. For example,
administrators can easily configure how much disk space to dedicate
to logs or trace, or how long to retain log and trace records, and
leave the management of log and trace content up to the server. As
another example all log, trace, System.out, and System.err content
can be accessed using one easy-to-use command (LogViewer), avoiding
any possible confusion over which file to access for certain content.
- HPEL has been
designed to make working with log and trace content more flexible
and effective than the basic logging facility. Log and trace content
can be easily filtered to show only the records that are of interest.
You can use the command line (see the description of the HPEL LogViewer
command), or developers can create powerful log handling programs
using the HPEL API.
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Hung threads in Java Platform, Enterprise Edition applications
An application server monitors the
activity of threads on which system alarms execute. When a system
alarm thread has been active longer than the time defined by the alarm
thread monitor threshold, the application server logs the following
warning in the system log. This message indicates the name of the
thread that is not responding, the length of time that the thread
has already been active, and the exception stack of the thread, which
identifies the system component.